In recent years, display elements of an image display device, such as a television device, are in a transition from the conventional cathode-ray tube to flat display panel, such as liquid crystal panel or plasma display panel, making it possible to provide a flat image display device. The liquid crystal panel of a liquid crystal display device does not emit light by itself, and therefore the display device requires a backlight unit as a separate lighting device. The backlight unit may be generally categorized by mechanism into a direct type and an edge light type. In order to further reduce the thickness of the liquid crystal display device, it is preferable to use an edge light backlight unit, as described in Patent Document 1 indicated below.
The backlight unit described in Patent Document 1 includes a light guide plate, an LED facing an end portion of the light guide plate, an LED board on which the LED is mounted, and a lead frame electrically connecting the LED board to an external power supply circuit board. The lead frame includes a clip-like terminal on one end to be soldered to the LED board, and a flat-plate terminal on the other end to be soldered to the external power supply circuit board. Thus, the lead frame relays the supply of electric power to the LED board.    Patent Document 1: Japanese Unexamined Patent Publication No. 1999-133394